Hummer H2. Manual - part 1343

1. Separate the connector halves.  

2. Visually inspect the connector halves for contamination. Contamination may result in a white or green 

build-up within the connector body or between terminals. This causes high terminal resistance, 
intermittent contact, or an open circuit. An underhood or underbody connector that shows signs of 
contamination should be replaced in its entirety: terminals, seals, and connector body.  

3. Using an equivalent male terminal from the J-38125 , test that the retention force is significantly different 

between a good terminal and a suspect terminal. Replace the female terminal in question. See Special 
Tools and Equipment .  

Flat Wire (Dock and Lock) Connectors 

or  

There are no serviceable parts for flat wire (dock and lock) connectors on the harness side or the component 
side. 

Follow the procedure below in order to test terminal contact. 

1. Remove the component in question.  

2. Visually inspect each side of the connector for signs of contamination. Avoid touching either side of the 

connector as oil from your skin may be a source of contamination as well.  

3. Visually inspect the terminal bearing surfaces of the flat wire circuits for splits, cracks, or other 

imperfections that could cause poor terminal contact. Visually inspect the component side connector to 
ensure that all of the terminals are uniform and free of damage or deformation.  

4. Insert the appropriate adapter from the J 42675 on the flat wire harness connector in order to test the 

circuit in question. See Special Tools and Equipment .  

INDUCING INTERMITTENT FAULT CONDITIONS 

In order to duplicate the customer's concern, it may be necessary to manipulate the wiring harness if the 
malfunction appears to be vibration related. Manipulation of a circuit can consist of a wide variety of actions, 
including: 

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Wiggling the harness  

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Disconnecting a connector and reconnecting  

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Stressing the mechanical connection of a connector  

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Pulling on the harness or wire in order to identify a separation/break inside the insulation  

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Relocating a harness or wires  

All these actions should be performed with some goal in mind. For instance, with a scan tool connected, 
wiggling the wires may uncover a faulty input to the control module. The snapshot option would be appropriate 
here. Refer to Scan Tool Snapshot Procedure . You may need to load the vehicle in order to duplicate the 
concern. This may require the use of weights, floorjacks, jackstands, frame machines, etc. In these cases you are 
attempting to duplicate the concern by manipulating the suspension or frame. This method is useful in finding 

 

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2004 ACCESSORIES & EQUIPMENT Wiring Systems - Hummer H2

  

harnesses that are too short and their connectors pull apart enough to cause a poor connection. A DMM set to 
Peak Min/Max mode and connected to the suspect circuit while testing can yield desirable results. Refer to 
Testing for Electrical Intermittents . 

Certainly, using the senses of sight, smell, and hearing while manipulating the circuit can provide good results 
as well. 

There may be instances where circuit manipulation alone will not meet the required criteria for the fault 
condition to appear. In such cases it may be necessary to expose the suspect circuit to other conditions while 
manipulating the harness. Such conditions would include high moisture conditions, along with exceptionally 
high or low temperatures. The following discusses how to expose the circuit to these kinds of conditions. 

Salt Water Spray 

Some compounds possess the ability to conduct electricity when dissolved in water such as ordinary salt. By 
mixing table salt with water in sufficient quantities, you can enhance the conductive properties of water so that 
any circuit which may be sensitive to moisture will more readily fail when liberally sprayed with this mixture. 

Mixing 0.35L (12 oz) of water with approximately 1 tablespoon of salt will yield a salt solution of 5 percent. 
Fill a normal spray bottle with this mixture. This mixture is sufficient to enhance the water's own conductivity. 
This may cause the circuit to fail more easily when sprayed. Once the mixture is completed, spray the suspect 
area liberally with the solution. Then, while monitoring either a scan tool or DMM, manipulate the harness as 
discussed previously. 

High Temperature Conditions 

Tools Required 

J 25070 Heat Gun. See Special Tools and Equipment . 

High Temperature Conditions 

If the complaint tends to be heat related, you can simulate the condition using the J 25070 . See Special Tools 
and Equipment . 

Using the heat gun, you can heat up the suspected area or component. Manipulate the harnesses under high 
temperature conditions while monitoring the scan tool or DMM to locate the fault condition. 

The high temperature condition may be achieved simply by test driving the vehicle at normal operating 
temperature. If a heat gun is unavailable, consider this option to enhance your diagnosis. This option does not 
allow for the same control, however. 

Low Temperature Conditions 

Depending on the nature of the fault condition, placing a fan in front of the vehicle while the vehicle is in the 
shade can have the desired effect. 

 

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2004 ACCESSORIES & EQUIPMENT Wiring Systems - Hummer H2

  

If this is unsuccessful, use local cooling treatments such as ice or a venturi type nozzle (one that provides hot or 
cold air). This type of tool is capable of producing air stream temperatures down to -18°C (0°F) from one end 
and 71°C (160°F) from the other. This is ideally suited for localized cooling needs. 

Once the vehicle, component, or harness has been sufficiently cooled, manipulate the harness or components in 
an effort to duplicate the concern. 

TESTING FOR ELECTRICAL INTERMITTENTS 

Perform the following procedures while wiggling the harness from side to side. Continue this at convenient 
points (about 6 inches apart) while watching the test equipment. 

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Testing for Short to Ground  

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Testing for Continuity  

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Testing for a Short to Voltage  

If the fault is not identified, perform the procedure below using the MIN MAX feature on the J 39200 DMM. 
This feature allows you to manipulate the circuit without having to watch the J 39200 . The J 39200 will 
generate an audible tone when a change is detected. 

1. Connect the J 39200 to both sides of a suspected connector (still connected), or from one end of a 

suspected circuit to the other. Refer to Troubleshooting with a Digital Multimeter for information on 
connecting the J 39200 to the circuit.  

2. Set the rotary dial of the J 39200 to the V (AC) or V (DC) position.  

3. Press the range button of the J 39200 in order to select the desired voltage range.  

4. Press the MIN MAX button of the J 39200 . The J 39200 displays 100 ms RECORD and emits an 

audible tone (beep). 

5. Simulate the condition that is potentially causing the intermittent connection, either by wiggling the 

connections or the wiring, test driving, or performing other operations. Refer to Inducing Intermittent 
Fault Conditions .  

6. Listen for the audible Min Max Alert which indicates that a new minimum or maximum value has been 

recorded.  

7. Press the MIN MAX button once in order to display the MAX value and note the value.  

8. Press the MIN MAX button again in order to display the MIN value and note the value.  

9. Determine the difference between the MIN and MAX values. 

IMPORTANT: The J 39200 must be used in order to perform the following procedure since 

the J 39200 can monitor current, resistance or voltage while recording the 
minimum (MIN), and maximum (MAX) values measured.

IMPORTANT: The 100 ms RECORD mode is the length of time an input must stay at a 

new value in order to record the full change.

 

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2004 ACCESSORIES & EQUIPMENT Wiring Systems - Hummer H2

  

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If the variation between the recorded MIN and MAX voltage values is 1 volt or greater an 
intermittent open or high resistance condition exists. Repair the condition as necessary.  

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If the variation between the recorded MIN and MAX voltage values is less than 1 volt an 
intermittent open or high resistance condition does not exist.  

SCAN TOOL SNAPSHOT PROCEDURE 

Snapshot is a recording of what a control module on the vehicle was receiving for information while the 
snapshot is being made. A snapshot may be used to analyze the data during the time a vehicle condition is 
current. This allows you to concentrate on making the condition occur, rather than trying to view all the data in 
anticipation of the fault. The snapshot contains information around a trigger point that you have determined. 
Only a single data list may be recorded in each snapshot. The Scan Tool has the ability to store 2 snapshots. 
The ability to record 2 snapshots allows comparing hot versus cold and good versus bad vehicle scenarios. The 
snapshots are stored on a first-in, first-out basis. If a third snapshot is taken, the first snapshot stored in the 
memory will be lost. 

Snapshots can be 1 of 2 types: 

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Snapshot - taken from the Snapshot menu choice  

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Quick Snapshot - taken from the Data Display soft key choice, does not contain DTC information  

When a snapshot is taken, it is recorded on the memory card and may contain as many as 1200 frames of 
information. Because the snapshot is recorded onto the memory card, snapshots are not lost if the Scan Tool is 
powered down. 

The snapshot replay screen has a plot soft key that can be of great value for intermittent diagnosis. The snapshot 
plot feature can help you to quickly determine if a sensor is outside of its expected values by plotting 3 
parameters at a time. The data will be displayed both graphically and numerically showing the minimum and 
maximum values for all frames captured. This is helpful, especially if the fault occurs only once and does not 
set a DTC. 

CIRCUIT PROTECTION - FUSES 

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Wiring Systems - Hummer H2